This paper describes a study aimed at evaluating the effect of selecting sires based on their breeding values for milk yield estimated in their countries of origin on reproductive performance of their daughters on large-scale dairy farms in Malawi. To do this an analysis was done using 2362 records of purebred Holstein Friesian cattle kept in Central and Southern Malawi from 1986 to 1996. Fixed effects of sire group, herd, year and season of calving were tested and random effects of dam and cow were included in the statistical model applied. (Co)variance components were estimated through the restricted maximum likelihood (REML) procedure. Mean number of services per conception (NSC) was 1.50, gestation interval (GI) was 277days, calving interval between first and second parity (CI1) was 416 days, calving interval between second and third parity two and three (CI2) was 408 days, and age at first calving (AFC) was 32.5 months. In general the majority of the reproductive traits were affected by the non-genetic factors of herd, year and season. Sire group, a proxy of the breeding strategy, had a significant effect on AFC (p<0.01) and CI2 (p<0.05). Factors that had significant effects (p<0.01) on most of the reproductive traits in the study were herd, year of insemination, year of calving, and season of insemination. Phenotypic correlation between NSC and AFC was 0.19, between NSC and GI was -0.05, while that between NSC and CI2 was 0.14. Heritability estimates for NSC, GI, CI1, and AFC were, 0.04, 0.10, 0.001, and 0.20, respectively. The high variation due to non-genetic factors and the low heritability estimates for the reproductive traits indicate that much improvement could be made through improved management, husbandry practices, and strategically utilizing environmental factors.

Range forages consumed by free-range goats are commonly deficient in protein, energy and minerals resulting in low productivity of the goats. The main objective of this study was to evaluate the effect of whole pumpkin seed meal supplementing diet on growth performance and semen quality of free-range goats. Thirty Malawian local bucks with an initial weight of 12.4±0.3 kg and age of 6 months were studied in completely randomised design. The treatments were: free-grazing with either supplementing diet of pumpkin seed meal or soybean meal and grazing only. The supplementing diets were mixed with maize bran to make them comparable. The supplementing diets were offered to goats (500 g each goat) before grazing (7:00 am) in individual pens followed by free graze for 7h. The experiment ran for 150 days. The measurements included: feed and refusals of the supplementing diet, live body weight, scrotal circumference and semen quality characteristics. The intake of supplementing diets was high in bucks consuming soybean supplementing diet than pumpkin seed meal supplementing diet (P = 0.0489). Bucks supplemented with either soybean or pumpkin seed meal had higher final weight and average daily gain (P < 0.05) than the non-supplemented goats. However, the final live body weight and average daily gain did not differ (P = 0.639) between goats on soybean and pumpkin seed meal supplementing diets. The bucks supplemented with pumpkin seed meal had the widest scrotal circumference (P < 0.05) of all the treatments studied. The bucks fed a supplementing diet containing pumpkin seed meal had higher semen pH (P < 0.05) than bucks on sole grazing group and soybean supplementing diet. Bucks on pumpkin seed supplementing diet had the greatest scores (P < 0.05) on total sperm motility and progressive motility; and sperm concentration followed by the bucks on soybean and the bucks on grazing only had the lowest score. The whole pumpkin seed meal could be used to improve productive performance and semen quality characteristics of free-ranging bucks.

Pasture research led by the International Center for Tropical Agriculture (CIAT) and national institutions during the 80's and 90's, contributed with new Brachiaria species with various characteristics and uses that were incorporated with success in livestock production systems in the lowlands of Latin America. Brachiaria brizantha, Brachiaria dictyoneura, Brachiaria humidicola and Brachiaria ruziziensis are some of the forage materials released by research institutions in the region. Despite its indisputable advantages, the Brachiaria genus presents limitations because of its low tolerance to prolonged droughts and its high susceptibility to spittlebug, a pest that causes considerable economic losses to the livestock industry. Thus, most recent research in CIAT's Brachiaria breeding program has focused on the development of a second generation of Brachiaria grasses: outstanding agronomic characteristics, establishment vigor, good sprout capacity, high biomass production and nutritional quality, good seed production, resistant to Rhizotocnia and to multiple spittlebug species. The results of this effort have conveyed to the recent release of Mulato grass, the first hybrid of the Brachiaria genus obtained by CIAT's genetic improvement program. In the waiting list of the second generation of Brachiaria grasses is hybrid #4624 (CIAT 36087), to be released in 2005, having a similar forage quality as Mulato and with all the attributes defined for the second generation of Brachiaria grasses. Moreover, several other hybrids are in advanced stages of evaluation and close to being released as commercial cultivars. The potential economic impact of the adoption of new Brachiaria hybrids on livestock production systems was evaluated using the Economic Model MODEXC. Two regions were considered in Colombia: the Northern Coast and the Eastern Plains. In Mexico, the tropical region; and in Central America, its six constituent countries. The model estimates the economic benefits attributable to the utilization of the new materials, disaggregating per country, region, ecosystem, production system and large social groups (consumers and producers). It works with two types of parameters: the technical ones that characterize the new technology and its process of dissemination, and the economic ones representing the conditions of market supply and demand of both beef and milk affected by the technical change. The benefits of the new technology (from the year 2007) were calculated for a period of 20 years and the results were expressed in terms of the net present value (NPV) and annuities. The estimates were made using alternatively an economic framework of open and closed economy. In a closed economy, without international trade, the NPV of the technological benefits was estimated at US$4,166 million, of which 54% would be generated by the marketing of beef and the rest by milk. Most of the benefits were concentrated in Mexico, US$2,831 (68%); followed by Colombia, US$960 million (23%), and Central America, US$363 million (9%). In order to have criteria on the extent of the estimated technological benefits, the value of beef and milk yield during 2003 was calculated in the reference countries. The NPV is equivalent to 44% of the value of that year, ranging between 16% in Honduras and 78% in Nicaragua. The results show the importance of the dual purpose livestock production system. In most countries, more than half of the technological benefits was generated in this system: Colombia 70%, Central America 62%, and Mexico 50%. When a country is self-sufficient and the surplus resulting from the technical improvements is marketed domestically, the benefits are transferred to consumers who are favored with the reduction in prices, making possible for them to increase consumption. In the case of a closed economy, consumers would capture 83% of total benefits. Trade liberalization implies a re-distributive process favoring producers. Export purchases increase total demand and restrain the fall of domestic prices. In an open-market economy, the share of benefits to producers would rise to 46%. Research investment is conceived as a primary mechanism to achieve two of the most basic social goals: 1) poverty reduction and improvement in equity, and 2) the promotion of economic growth. Having this premise, in order to establish to what extent this technical change contributes to the fulfillment of these goals, the acquired benefits were estimated for the most vulnerable population groups: a) The two quintiles of poor consumers, representing 40% of total population, and b) the small producers. In both schemes, open or closed economy, both groups receive more than one-fourth of the benefits from technical change, 27% and 31%, respectively. This is equivalent to a NPV ranging between US$1,137 to 1,303 millions. Because the hybrids require better soils or fertilizer inputs to maintain forage biomass productivity and quality, the study was made with conservative hypotheses about changes in productivity and the size of the area to be planted. Despite the definition of the levels of critical variables, especially those associated with the productivity and the adoption of the new Brachiaria hybrids, conservative criteria were considered in order to avoid overestimating the benefits; it is important to evaluate the sensitivity of these, against undesirable changes of those variables. For this purpose, three alternative scenarios were established: 1) The reduction of 50% of the area cultivated with new Brachiaria hybrids, 2) the reduction of 10% in the yields of the new materials, and 3) the increase of 50% in the total time of adoption. The most critical variable in the determination of the amount of benefits is yield (productivity) of the new technology, in terms of beef and milk per hectare. The elasticity of the benefits regarding the yields was estimated at 2.2 for Colombia and 1.8 for Central America and Mexico. This suggests that if the yield declines by 1%, the reduction of the social benefits is more than proportional. The social benefits are less elastic with regard to the area planted with new Brachiaria hybrids or the time of adoption. For example, in Colombia, if the area with improved materials declines by one percentage point, the benefits will diminish at approximately six tenths of one point. In all the proposed alternative scenarios, the investment in the development of these new pastures are economically attractive, despite the adverse circumstances proposed in these scenarios. The technological benefits expressed as an annuity (a fixed annual payment received for a specific number of years) shows that the investment for the development of new forage options is very low, less than US$ 20 million, compared with the annual benefits resulting from the use of these new materials.

The objective was to perform an ex-ante economic evaluation of new, legume-based forage alternatives available to farmers in Latin American tropical lowlands. These alternatives included grasses of the Brachiaria genus and the legumes Stylosanthes guianensis, Cratylia argentea, and Arachis pintoi. Case studies, involving farmers participating in the CIAT-led Tropileche Consortia convened by ILRI, were conducted in the forest margins of Pucallpa (Peru) and in the hillsides of the dry tropics of Esparza (Costa Rica) and Esquipulas (Nicaragua). A linear programming farm model developed by CIAT to maximize income was used for this analysis. Animal management parameters were based on farm averages at each reference site evaluated so that they represented current management conditions. Similarly, the model incorporated the prices of inputs and products typical of each country. A constant herd size was assumed for all alternatives evaluated. Production costs per kilogram of milk were estimated as the maximum expression of competitiveness, using three cow productivity parameters: the current average production per lactation (800 kg in Peru, 1,000 kg in Nicaragua, and 1,350 kg in Costa Rica); and two postulated parameters: 1,500 kg/lactation and 2,000 kg/lactation. For all forage options, key factors analyzed were (1) milk production costs resulting from implementing each forage alternative; (2) the investment required to establish each option, assuming the same number of milking cows and herd fertility; (3) the feasibility of obtaining credit with a local bank to invest in a forage alternative; and (4) the percentage of pasture area on the farm freed for other uses as a result of establishing one of the forage alternatives. Results indicated that the forage alternatives evaluated significantly improved the competitiveness of dual purpose farms in the hillsides of Nicaragua and Costa Rica, reducing the cost of producing milk between 13% and 37% with increased stocking rates, releasing up to 36% of area allocated to pastures. However, under current commercial banking conditions (real interest rates of 13% in Costa Rica and 18% in Nicaragua with payback periods of 5 years), the implementation of the options evaluated were not financially viable except for the establishment of Cratyla with sugarcane for dry-season feeding and Stylosanthes for pre-weaned calves. For all options to be implemented with commercial credit, a longer payback period was needed (8-10 years) and lower real interest rates (5-10%). The case of the forest margins of Pucallpa, was different, as none of the forage options evaluated, except Stylosanthes for pre-weaned calves, improved the competitiveness of farms under current management and production conditions due to low milk yields per cow and low proportion of herd in milk, which increased depreciation cost/cow to levels which were not viable. In addition, Pucallpa has an excess supply of forage biomass from a reduced herd inventory during the 80s and a limited fresh milk market which makes adoption of improved forages low attractive by farmers.

The present study was conducted to investigate the effect of fruits maturity stages at harvest on chemical composition, in vitro digestibility and in sacco degradability of Ficus surfruits (FSF). The treatments involved different maturity stages of Ficus sur fruits . Color, moisture content, and texture were used to distinguish among the fruit maturity stages. Fruits at early, mid, and late stages of maturity were collected from five trees and analyzed. The proximate composition of the fruits varied only slightly (0 to 3%) with the progress in maturity of the fruits. The exception was the DM content which increased from 45 to 87% with increasing maturity. The condensed tannins were low (<2%) for all the stages of maturity. In vitro and in sacco measurements indicated that the fruits at all stages of maturity were theoretically only slightly inferior to cereal grains as sources of digestible energy. However, the high washing loss in the in sacco study (38 to 42%) indicates that much of the digestible carbohydrate was in the form of soluble sugars which, depending on the levels used in the diet, could compromise the realizable net energy value of the diet. As in cereal grains, the crude protein content was relatively low (7.07 to 7.33% in DM).

Methane is considered to be the main greenhouse gas (GHG) emitted by livestock. One method for reducing methane emissions from ruminants is to improve production efficiency, which reduces methane emissions per unit of product (FAO, 2010; Gworgwor, Mbahi, and Yakubu, 2006). There are many researches about prebiotics which can reduce methane production in livestock, for example, galacto-oligosaccharides reduced methane emission up to 11% (litres/day) (Zhou et al., 2004). There is almost no information about prebiotic inulin, so the aim of this research was to determine the impact of different dosages of inulin concentrate (50%) on the increase of calves’ body weight and its impact on methane emission, as well as to find out how the results change if it is added to barley flour not to milk as in our previous research. Approximately fifty days old, clinically healthy, different Holstein Friesian crossbreed calves kept in groups of 8, in a partly closed space with natural ventilation through windows were included in this research. Eight calves were in the control group (CoG) and sixteen received inulin (Pre12 (n = 8), Pre24 (n = 8)). At the beginning of the experiment – the 28th and 56th day - we determined each calf’s weight and measured the methane level in the rumen by using the PICARROG-2508 gas analyser (Fleck, 2013). We concluded that inulin supplement significantly (p ≤ 0.05) increased the live weight gain comparing Pre24 and CoG. The highest methane production on 1 kg of body weight at the end of the research was detected in Pre24 – 1.24 mg mE-3 and the lowest in CoG – 0.99 mg mE-3.

Wheat crown rot is a harmful disease that can be caused by different pathogens. The control of this disease is complicated because of the diversity of pathogens and an insufficient efficacy of fungicides; therefore, the agronomic practices of wheat production are an important tool for reducing the disease development. The aim of this study was to estimate the incidence of wheat crown rot depending on soil tillage system and on the pre-crop of wheat in the year 2016. The field experiment was carried out at the Research and Study farm ‘Peterlauki’ of the Latvia University of Agriculture in the autumn of 2008. The data obtained in 2016 are analysed in this study: A – soil tillage system: 1 – traditional soil tillage with ploughing at the depth of 22 – 24 cm, 2 – reduced soil tillage with disc harrowing up to the depth of 10 cm; B – pre-crop of winter wheat: 1 – wheat, 2 – oilseed rape, 3 – faba beans. The incidence of crown rot was not influenced by soil tillage system, but the impact of pre-crop was significant (p = 0.006). The level of disease was essentially higher in continuous wheat sowings. The experiments showed that the main causal agents of the disease were Fusarium spp. and Oculimacula spp. The spectrum of pathogens was not dependent on a particular agronomic practice.

Organic farmers need varieties adapted to variable growing conditions, because in organic farms environmental conditions significantly vary in soil nutrient status, weed and disease pressure not only between years, but also among farms within a season. Modern varieties developed under high input agricultural systems do not always perform well under organic growing conditions. Therefore, farmers need such varieties of cereals that can adapt to variable growing conditions and maintain productivity. One of the ways to promote adaptation to environment is growing of variety mixtures. Field trials were conducted during 2014 – 2016 under organic and conventional farming systems in two locations with an aim to estimate the advantages of barley mixtures in respect of yield and its stability. The trial consisted of eight mixtures of barley varieties and breeding lines, components of mixtures in pure stand and three check varieties. The mixtures were combined by using two, three and five components. Three mixtures, each in one out of 11 environments significantly out–yielded, but one mixture had significantly lower yield than the average value of their components. Some mixtures showed a tendency to out–yield the average of components in both farming systems. All mixtures insignificantly out–yielded check varieties in 2015, but in 2016, yield was within the range between varieties with lowest and highest yield. The results of yield stability analysis showed that mixtures could be used as one of the approaches to stabilize yield – only one of eight mixtures had a lower yield than the average over all environments.